1. Field of the Invention
The present invention generally relates to a radio frequency identification system (hereinafter, referred to as “RFID system”) having a radio frequency (hereinafter, referred to as “RF”) tag, and more specifically, to a technology of variably changing a RF transport protocol of a RF tag by using a field programmable gate array (hereinafter, referred to as “FPGA”) in various ways.
2. Description of the Related Art
Automatic identification systems are known. Existing systems use tags such as bar codes, magnetic cards, IC cards, and/or RF tags to identify various objects. Of these systems, RFID based systems wirelessly identify information written in a tag using a very high frequency or a long wave.
FIG. 1 is a diagram illustrating an exemplary RFID system. The RFID system shown includes a read/write terminal 10 for exchanging data with RF tag 20. The read/write terminal 10 includes a transmitter 12 for transmitting data to the RF tag 20 through the antenna, a receiver 14 for receiving data from the RF tag 20 through the antenna, and a processor 16 for analyzing the received data to obtain native information of the RF tag 20. The RF tag 20 converts an electric wave received from the read/write terminal 10 into electric power, and is activated by the power to read data stored in a memory in a RF chip. This data is then transmitted by the RF tag 20 to the read/write terminal 10.
FIG. 2 is a detailed diagram illustrating the RF tag 20 of FIG. 1. The RF tag 20 includes an antenna coil 22 for transmitting an electric wave to and receiving an electric wave from the read/write terminal 10, and a RF transmitting/receiving unit 24 for processing data transmitted and received so as to enable RF communication with the read/write terminal 10 through the antenna coil 22. In addition, the RF tag 20 includes a protocol microprocessor 26 that processes data applied through a bus 28 and stored in a memory, depending on a predetermined RF transport protocol.
Known RF tags, such as RF tag 20 described above, are limited in their customizability and adaptability for various purposes. Specifically, in operation RFID specifications, such as operating frequency, memory capacity and technical format of information inputted in a memory, vary from one manufacturer to another. As such, a RF tag designed to meet a specific RFID requirement typically cannot be used in other applications. For example, 13.56 MHz, 800˜900 MHz and 2.45 GHz operating frequencies are often used, and may require differently designed antenna coils 22 and/or transmission protocols. Additionally, some specifications require memories with 96 bit read capability, while others require memories with 1280 byte read/write capability. Finally, different technical formats are often used for information inputted in the memory. As such, manufacturers of known RF tags manufacture different RF tags for different specifications.
Thus, a need exists for an improved RFID system and/or improved RF tags. Other problems with the prior art not described above can also be overcome using the teachings of the present invention, as would be readily apparent to one of ordinary skill in the art after reading this disclosure.